use std::error;

/// Application result type.
pub type AppResult<T> = std::result::Result<T, Box<dyn error::Error>>;

/// Application.
#[derive(Debug)]
pub struct App<'a> {
    /// Is the application running?
    pub running: bool,
    /// counter
    pub counter: u8,

    pub tab_titles: Vec<&'a str>,
    pub current_tab: usize,
}

impl<'a> Default for App<'a> {
    fn default() -> Self {
        Self {
            running: true,
            counter: 0,
            tab_titles: vec!["History", "New Entry", "Accounts"],
            current_tab: 0,
        }
    }
}

impl<'a> App<'a> {
    /// Constructs a new instance of [`App`].
    pub fn new() -> Self {
        Self::default()
    }

    /// Handles the tick event of the terminal.
    pub fn tick(&self) {}

    /// Set running to false to quit the application.
    pub fn quit(&mut self) {
        self.running = false;
    }

    pub fn next_tab(&mut self) {
        self.current_tab += 1;
        if self.current_tab >= self.tab_titles.len() {
            self.current_tab = 0;
        }
    }

    pub fn prev_tab(&mut self) {
        if self.current_tab == 0 {
            self.current_tab = self.tab_titles.len() - 1;
        } else {
            self.current_tab -= 1;
        }
    }

    pub fn increment_counter(&mut self) {
        if let Some(res) = self.counter.checked_add(1) {
            self.counter = res;
        }
    }

    pub fn decrement_counter(&mut self) {
        if let Some(res) = self.counter.checked_sub(1) {
            self.counter = res;
        }
    }
}